A conventional truck has a cab at its front end and the truck is usually loaded or unloaded at its rear end. If it is necessary to make a 180.degree. change in direction to approach or leave an unloading zone or a loading zone, the driver must take time to make a U-turn if room and conditions permit. If there is not sufficient room for a U-turn but there is sufficient room for limited maneuvering, the driver may turn the truck around by appropriate steering to make partial turns while alternately driving the truck forward and rearward. Such maneuvering not only means loss of time but also involves serious hazard because the driver has only a limited view of the path of travel when he is backing the truck.
If an unloading zone or a loading zone is at the dead end of a narrow lane, the truck must back up along the lane to reach the zone in order to have the truck positioned properly for unloading or loading. Backing up a truck in this manner also involves loss of time and is also hazardous.
It is apparent, therefore, that there is pressing need for a truck construction that will eliminate the necessity for other than straightforward travel to reach or leave an unloading zone or a loading zone.